Karjakin-Aronian
Everyone plays as good as the opponent allows to. In this game Levon failed to impress because Sergey was really impressive.
White made a new move in a modern line of the Ruy Lopez –15.b3! Perhaps Black had to change his plan, keeping the king on f8. In this case he would have a chance to create some counterplay with his bishops: 15…Bc5 16.Bb2 Bg4!, which would compensate for the weakness of the e5-pawn. However, Aronian played in a more standard way, placing the king to e7, which led to big complications, and eventually lost a pawn.
Karjakin converted his advantage in a refined fashion. One cannot pass by the excellent 24.Nb6!, which transposed the game into a rook ending. Soon Black missed his last chance to resist: instead of 27…Rb5 he had to counterattack on the second rank by 27…Rd2!, and then Rb8-e8-e2.
In the game White managed to promote his pawn and defended against the perpetual.

Grischuk-Kasimdzhanov

I
found many unexpected resources in the analysis of this complicated
game. Kasimdzhanov employed a very risky but interesting plan in a
well-known variation of the Queen’s Gambit Accepted. I thought that
after 14.Nxb6 Black had to take with the c7-pawn, keeping the king’s
shelter intact. After 14…cxb6 White cannot retreat the knight from e2
because of the d4-pawn weakness, while 15.Ba4 is well met by 15…g5!
with strong counterplay for Black.
However, Rustam selected 14…axb6, allowing the
opponent to establish deadly-looking pressure against the c6-knight.
The ideas behind this move were clarified by the extremely tricky
maneuver 17…Qc8! – Black sacrificed a pawn for the initiative.

The subsequent moves did not look forced. For instance, instead of
19…fxe5 Black could play 19…Nc6! Later Kasimdzhanov did not find the
most accurate 25…Qa6!, which would allow continuing to play on equal
terms. After 25…Qb7? Grischuk destroyed Black’s defense by the powerful
26.a4!

In the time trouble that followed, the assessment varied from “White
wins” to “Black can hold”. On the 39th move White could win by 39.Qe4!
with the idea 39…Qg5+ 40.Kh1! Qxd2 41.Qa8#. However, Alexander played
39.Ra2, and Black overstepped the time limit, although he could put up
some resistance by 39…Rd8! Now 40.Qe4? Qg5+! loses for White. Of
course, even after 39…Rd8 White still has an edge, but the outcome of
the game could well be different.

Akopian-Leko
The Hungarian grandmaster outskilled the Armenian in opening
preparation. In the Meran Variation of the Slav Defense he surprised
the opponent with a refined novelty 17…Qd5! Black created strong
pressure. In my opinion White had to consider sacrificing an exchange
in order to seize the initiative. For instance, it is interesting to
look at 21.Bd2! Nb3 22.Rb4 Bxg2! (a fine resource) 23.Bxg2 Nxa1 24.Bc3.
Of course, such moves are easier to suggest that actually play on the
board.
Akopian decided to give up a pawn, and after a few accurate opponent’s
moves (23…Ba6!, 26…Qc2!) had to accept a difficult endgame without a
pawn, which he failed to hold. Leko’s technique in the final phase of
the game was perfect – a textbook example of converting the advantage!

Alekseev-Eljanov
A
tragic story! At the early phase of the game it looked like the Russian
is doomed to fall, however, it was the Ukrainian who perished in the
end.
In a fashionable line of the Queen’s Gambit Eljanov employed an
excellent novelty 12…Qe8! (earlier Black only played 12…b5, allowing
the attacking 13.a4!). Alekseev reacted poorly. He couldn’t play 13.Be2
due to 13…Ne4!, but he had to make a preparatory move for the
development – 13.Qc2! The move he selected – 13.f3?! – left the White’s
king in the center and allowed Black advancing his queenside pawns.
Black’s advantage became absolutely clear by the 20th move. I think the
most accurate solution was 20…Bd7! In this case Black could prepare the
с4-с3 under the perfect circumstances, as White’s most natural defense
21.Nb1 Rfc8! 22.Nc3 (otherwise c4-c3) 22…Nxc3 23.Qxc3 Bxg4! loses a
pawn.
Pavel wasted a tempo, allowing White to make a useful move – 20...Re8
21.h3, and then started playing on the queenside, which did not make
the desired impact. Evgeny defended well, and his bluff 26.h4! shook
the opponent’s confidence. Pavel started making mistakes. His 26…Bb5?
was a grave error, changing the evaluation dramatically from “almost
equal” to “a huge advantage to White”. The advantage was duly converted
into a victory.

Bacrot-Svidler
The first impression of a non-conflict game is wrong. There was real
tension in it. In the Chigorin Variation of the Ruy Lopez the players
covered the entire board with solid pawn chains. White had a small
loophole on the kingside, but in order to use it he had to dare
sacrificing material. The best opportunity occurred, in my opinion, on
the 30th move. I think White could play 30.Nf5!? gxf5 31.gxf5, and then
slowly increase pressure by g2-g4, doubling the rooks and maybe even
rushing the kingside pawns h3-h4 and g4-g5. Surprisingly, he could
afford playing in such style without a piece and almost at no risk!
Black only could wait behind bars...
After the move played in the game – 30.Bh6 – Svidler closed all the doors by 30…g5!, and a draw became inevitable.

Ivanchuk-GelfandThis game was very interesting, and it seems both players conducted
it almost perfectly. In the Slav Defense White got the bishop pair, and
Black obtained active piece play against the enemy king.
I think Ivanchuk incorrectly allowed the Black’s queen to h3. Instead
of the rushy 18.e4 I suggest the prophylactic 18.Kg2! – the king can
protect himself! After that White has all the chances to prevail in the
center.
After Black organized the scary setup “Qh3 + Ng4”, White’s advantage
evaporated. Gelfand masterfully increased tension (21…Be3!, 25…f5!),
and then forced the move repetition by daring cavalry ride 28…Nc1!

Mamedyarov-KamskyIn the Gruenfeld Defense Black made an interesting novelty, but we
did not get a chance to see the depth of Gata’s preparation. The
critical line is probably 14.dxc6 followed by trading the queens,
however, Shakhriyar reacted in a very tricky fashion. He traded queens
in a different way, but failed to get any real advantage. Soon White’s
advanced pawns became targets of Black’s counterattack.
It was followed by exchange of logical and easy-to-calculate (at the
grandmaster level at least) tactical blows that resulted in an equal
rook ending, which ended peacefully.